Body Fat Percentage Calculator
Estimate your body fat percentage using the US Navy method. Enter your tape measurements to calculate body fat, fat mass, and lean mass. All calculations run in your browser.
Your Measurements
Results
Estimated Body Fat Percentage
AverageFat Mass
Lean Mass
Body Fat Categories (Male)
How to Measure
Neck
Measure just below the larynx (Adam's apple). Keep the tape level and snug but not tight.
Waist
Measure at your navel (belly button) level. Stand relaxed and don't suck in your stomach.
Hip (Women)
Measure at the widest point of your hips and buttocks. Keep the tape level around your body.
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Frequently Asked Questions
How accurate is the US Navy body fat method?
The US Navy method is generally accurate within 1-3% of body fat compared to more advanced methods like DEXA scans. It works best for people with average body proportions. Results may be less accurate for very muscular individuals or those with unusual fat distribution patterns.
What is a healthy body fat percentage?
Healthy body fat ranges differ by gender. For men, 14-17% is considered fitness level and 18-24% is average. For women, 21-24% is fitness level and 25-31% is average. Essential fat (minimum needed for health) is 2-5% for men and 10-13% for women. Going below essential fat levels is dangerous.
How should I take measurements for the US Navy method?
Measure your neck circumference just below the larynx (Adam's apple), keeping the tape level. Measure your waist at the navel (belly button) level. For women, also measure hips at the widest point. Use a flexible tape measure and keep it snug but not compressing the skin. Measure first thing in the morning for consistency.
Why does the calculator need different measurements for men and women?
Men and women store fat differently due to hormonal differences. Women typically carry more fat around the hips and thighs, so hip measurement is needed for accuracy. The US Navy formulas account for these gender-specific fat distribution patterns to provide more accurate estimates.
Understanding Body Fat Percentage
Body fat percentage is the proportion of your total body weight that is composed of fat tissue. Unlike BMI, which only considers height and weight, body fat percentage provides a more meaningful picture of your body composition and overall health. Two people with the same BMI can have very different body fat levels depending on their muscle mass and fat distribution.
The US Navy method, developed in the 1980s for military fitness assessments, estimates body fat using circumference measurements of the neck, waist, and hips. It applies a logarithmic formula to these measurements along with height to produce a body fat estimate. While not as precise as laboratory methods like DEXA scanning or hydrostatic weighing, the US Navy method is widely used because it requires only a tape measure, making it accessible for regular self-monitoring.
Maintaining a healthy body fat percentage is associated with reduced risk of cardiovascular disease, type 2 diabetes, and other metabolic conditions. However, going too low can be equally harmful. Essential fat, needed for normal hormonal and reproductive function, should never be eliminated. For most people, aiming for the fitness or average range provides the best balance of health and performance. Tracking body fat over time is more valuable than any single measurement, as trends reveal whether your diet and exercise habits are moving you in the right direction.